Banknote validators are now commonly used in different types of vending machines for receiving banknotes, determining denominations and the authenticity thereof. Accepted banknotes are stored in a banknote cassette and the vending machine is authorized to proceed with delivery of product in accordance with the credit value provided the customer. Banknote validators are also commonly used in gaming machines.
Banknotes of most major currencies on average have a useful life of approximately six months. The condition of the banknote greatly varies between a clean crisp banknote and a banknote that is relatively dirty with a deteriorated substrate. Banknotes have a series of security features which are examined by the validator and a prediction of the authenticity of the banknote is made. It can be appreciated that the validator must make an appropriate determination of a received banknote, however, as the condition of the banknote deteriorates, the evaluation is more difficult.
In addition, it has been found that deterioration of a banknote increases, the likelihood of the banknote being jammed in the validator, either during insertion and/or rejection of the banknote is much higher. This jamming of banknotes is a significant problem as validators are often used in an unmanned location and this causes user inconvenience and frustration. As the location is unmanned the user may seek to damage the device for not functioning properly and it is also inconvenient for the operator as a service call is required and a customer's complaint must be dealt with. If a banknote is to be rejected the validator must operate with a high probability of being capable of returning the banknote to the customer.
It can be further appreciated that a validator must operate with minimal instructions and be tolerant to a significant variation with respect to feeding of the banknote to the validator. Typically users are not particularly precise and thus a wide variation occurs. Therefore, the drive of the banknote through an evaluation passageway must properly align a banknote and move a banknote at a fairly high speed through the pathway while also being capable of returning a banknote should it be necessary. Jamming of the banknote either as it is processed through the device or as it is rejected from the device, should be minimized.
Prior art banknotes have used a series of three drive rollers for moving of a banknote through a curved banknote evaluation pathway where a series of sensors are disposed in the walls of the pathway for evaluation of the banknote as it moves therepast. Different validators have used optical sensors in combination with induction and capacitance sensors. These validators typically include an optical sensor for determining that a banknote has been inserted in the validator to activate the validator, and an optical sensor is used for determining that a banknote is about to leave the validating head and enter the banknote cassette. Banknotes typically become jammed at a large transition in the direction of the banknote pathway and adjacent the discharge of the banknote from the validating head.
The present invention provides an improved banknote validator which is less prone to banknote jamming and provides effective evaluation of the banknote as it is moved through the validating head.